fix: auto top-up stale prices from yfinance on startup — chart always shows latest data

dashboard/app.py

@@ -311,39 +311,60 @@ def _ensure_schema():
 
 @st.cache_resource
 def _ensure_prices():
-    """Fetch 2 years of price history from yfinance if the DB is empty.
-    Runs once per process — makes the app self-healing on fresh containers."""
-    conn = get_conn()
-    count = conn.execute("SELECT COUNT(*) FROM prices").fetchone()[0]
-    conn.close()
-    if count > 100:
-        return
+    """Keep prices up to date on every container start.
+    - If DB is empty: full 5-year backfill from yfinance.
+    - If DB has data but is stale (latest < yesterday): fetch missing days only.
+    Runs once per process lifetime."""
     try:
         import yfinance as yf
-        from data.db import get_conn as _gc
+        from datetime import date as _date, timedelta
+
+        conn = get_conn()
+        row = conn.execute(
+            "SELECT COUNT(*), MAX(date) FROM prices"
+        ).fetchone()
+        conn.close()
+        count, latest_date = row[0], row[1]
+
+        yesterday = (_date.today() - timedelta(days=1)).isoformat()
+
+        # Nothing to do if already current
+        if count > 100 and latest_date and str(latest_date) >= yesterday:
+            return
+
+        # Full backfill for empty DB, incremental top-up otherwise
+        period = "5y" if count < 100 else None
+        start  = None if period else (str(latest_date) if latest_date else "2020-01-01")
+
         symbols = list(SYMBOL_NAMES.keys())
-        ticker_data = yf.download(symbols, period="5y", auto_adjust=True, progress=False)
+        kwargs = dict(auto_adjust=True, progress=False)
+        if period:
+            kwargs["period"] = period
+        else:
+            kwargs["start"] = start
+
+        ticker_data = yf.download(symbols, **kwargs)
         if ticker_data.empty:
             return
-        conn2 = _gc()
+
+        conn2 = get_conn()
         for sym in symbols:
             try:
-                if len(symbols) == 1:
-                    df = ticker_data.copy()
-                else:
-                    df = ticker_data.xs(sym, axis=1, level=1) if sym in ticker_data.columns.get_level_values(1) else None
-                if df is None or (hasattr(df, 'empty') and df.empty):
+                df = ticker_data.xs(sym, axis=1, level=1) if len(symbols) > 1 else ticker_data.copy()
+                if df is None or df.empty:
                     continue
                 df = df.reset_index()
                 df.columns = [c.lower() for c in df.columns]
-                for _, row in df.iterrows():
+                for _, r in df.iterrows():
                     try:
                         conn2.execute(
-                            "INSERT OR REPLACE INTO prices (date,symbol,open,high,low,close,volume,adj_close) VALUES (?,?,?,?,?,?,?,?)",
-                            [str(row["date"])[:10], sym,
-                             float(row.get("open", 0) or 0), float(row.get("high", 0) or 0),
-                             float(row.get("low", 0) or 0), float(row.get("close", 0) or 0),
-                             float(row.get("volume", 0) or 0), float(row.get("close", 0) or 0)]
+                            "INSERT OR REPLACE INTO prices "
+                            "(date,symbol,open,high,low,close,volume,adj_close) "
+                            "VALUES (?,?,?,?,?,?,?,?)",
+                            [str(r["date"])[:10], sym,
+                             float(r.get("open")  or 0), float(r.get("high")  or 0),
+                             float(r.get("low")   or 0), float(r.get("close") or 0),
+                             float(r.get("volume") or 0), float(r.get("close") or 0)]
                         )
                     except Exception:
                         pass